1. Field of the Invention
The present invention relates to a roller bearing in which a roller is used as a rolling body to support a shaft of rotation and smoothly rotate the shaft under a load acting thereon.
2. Description of the Prior Art
As shown in FIGS. 13 to 15, the roller bearing, which has hitherto been used, is formed at any one of an outer race 51 and an inner race 52--in FIG. 13 at the inner race 52 and in FIG. 15 at the outer race 51--with flanges 53, in the region of which a plurality of rollers 54 are accommodated and interposed between the outer race 51 and the inner race 52. This construction prevents the rollers 54 from shifting in the direction of axis with respect to the inner race or outer race, and from falling down when the axis of the shaft is used vertically. The plurality of rollers 54 are retained at predetermined distances in the peripheral direction of the inner race by a retainer 55 (FIG. 14).
The retainer 55 is provided with a plurality of frames distributed at equal distances in the peripheral direction. Since the rollers 54 each are retained in each of the frames, when the rollers 54 are moved in rolling motion, contact frictions are inevitably caused between the rollers 54 and the retainer 55 and between the retainer 55 and the outer and inner races 51, 52, and the abrasion due to such frictions results in earlier damage of the retainer and seizure of the bearing.
Furthermore, since each roller 54 is retained by the retainer 55, the existence of the retainer reduces a free space between the inner and outer races 52 and 55, and the design of the flanges 53 supporting the rollers is limited.
If the flanges 53 are lower in height, the rollers 54 come into contact with the flanges 53 in the vicinity of the periphery of the rollers. The contact of the rollers 54 with the flanges in the vicinity of the periphery thereof inevitably causes greater contact frictions between the rollers 54 and the flanges 53 due to the rotation of the rollers and the revolution thereof relative to the outer and inner races. In addition to the contact with the flanges, the rollers are also brought into contact with the retainer 55, which results in abrasion of the rollers, retainer and the outer race or inner race.